This study investigated an analytical means of selecting the quickening time constant for the standardized Heads-Up Display flight path marker. The theoretically determined time constant allowed a faster, less resource intensive means of selecting the quickening time constant. The theoretically best time constant for pilot-aircraft handling qualities was equal to the airframe pitch attitude high frequency zero time constant, T-theta-2. Flight test indicated an empirical, more labor intensive method yielded better handling qualities, even though paper analysis indicated the theoretical method was better. The theoretically determined time constant gave slightly lower handling qualities. but was less costly to implement than the empirical method.